private FetchItem queueRedirect(Text redirUrl, FetchItem fit) throws ScoringFilterException {
CrawlDatum newDatum =
new CrawlDatum(
CrawlDatum.STATUS_DB_UNFETCHED, fit.datum.getFetchInterval(), fit.datum.getScore());
// transfer all existing metadata to the redirect
newDatum.getMetaData().putAll(fit.datum.getMetaData());
scfilters.initialScore(redirUrl, newDatum);
if (reprUrl != null) {
newDatum.getMetaData().put(Nutch.WRITABLE_REPR_URL_KEY, new Text(reprUrl));
}
fit = FetchItem.create(redirUrl, newDatum, queueMode);
if (fit != null) {
FetchItemQueue fiq = ((FetchItemQueues) fetchQueues).getFetchItemQueue(fit.queueID);
fiq.addInProgressFetchItem(fit);
} else {
// stop redirecting
redirecting = false;
reporter.incrCounter("FetcherStatus", "FetchItem.notCreated.redirect", 1);
}
return fit;
}
@SuppressWarnings("fallthrough")
public void run() {
activeThreads.incrementAndGet(); // count threads
FetchItem fit = null;
try {
// checking for the server to be running and fetcher.parse to be true
if (parsing && NutchServer.getInstance().isRunning()) reportToNutchServer = true;
while (true) {
// creating FetchNode for storing in FetchNodeDb
if (reportToNutchServer) this.fetchNode = new FetchNode();
else this.fetchNode = null;
// check whether must be stopped
if (isHalted()) {
LOG.debug(getName() + " set to halted");
fit = null;
return;
}
fit = ((FetchItemQueues) fetchQueues).getFetchItem();
if (fit == null) {
if (feeder.isAlive() || ((FetchItemQueues) fetchQueues).getTotalSize() > 0) {
LOG.debug(getName() + " spin-waiting ...");
// spin-wait.
((AtomicInteger) spinWaiting).incrementAndGet();
try {
Thread.sleep(500);
} catch (Exception e) {
}
((AtomicInteger) spinWaiting).decrementAndGet();
continue;
} else {
// all done, finish this thread
LOG.info("Thread " + getName() + " has no more work available");
return;
}
}
lastRequestStart.set(System.currentTimeMillis());
Text reprUrlWritable = (Text) fit.datum.getMetaData().get(Nutch.WRITABLE_REPR_URL_KEY);
if (reprUrlWritable == null) {
setReprUrl(fit.url.toString());
} else {
setReprUrl(reprUrlWritable.toString());
}
try {
// fetch the page
redirecting = false;
redirectCount = 0;
do {
if (LOG.isInfoEnabled()) {
LOG.info(
"fetching "
+ fit.url
+ " (queue crawl delay="
+ ((FetchItemQueues) fetchQueues).getFetchItemQueue(fit.queueID).crawlDelay
+ "ms)");
}
if (LOG.isDebugEnabled()) {
LOG.debug("redirectCount=" + redirectCount);
}
redirecting = false;
Protocol protocol = this.protocolFactory.getProtocol(fit.url.toString());
BaseRobotRules rules = protocol.getRobotRules(fit.url, fit.datum);
if (!rules.isAllowed(fit.u.toString())) {
// unblock
((FetchItemQueues) fetchQueues).finishFetchItem(fit, true);
if (LOG.isDebugEnabled()) {
LOG.debug("Denied by robots.txt: " + fit.url);
}
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_ROBOTS_DENIED,
CrawlDatum.STATUS_FETCH_GONE);
reporter.incrCounter("FetcherStatus", "robots_denied", 1);
continue;
}
if (rules.getCrawlDelay() > 0) {
if (rules.getCrawlDelay() > maxCrawlDelay && maxCrawlDelay >= 0) {
// unblock
((FetchItemQueues) fetchQueues).finishFetchItem(fit, true);
LOG.debug(
"Crawl-Delay for "
+ fit.url
+ " too long ("
+ rules.getCrawlDelay()
+ "), skipping");
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_ROBOTS_DENIED,
CrawlDatum.STATUS_FETCH_GONE);
reporter.incrCounter("FetcherStatus", "robots_denied_maxcrawldelay", 1);
continue;
} else {
FetchItemQueue fiq = ((FetchItemQueues) fetchQueues).getFetchItemQueue(fit.queueID);
fiq.crawlDelay = rules.getCrawlDelay();
if (LOG.isDebugEnabled()) {
LOG.debug(
"Crawl delay for queue: "
+ fit.queueID
+ " is set to "
+ fiq.crawlDelay
+ " as per robots.txt. url: "
+ fit.url);
}
}
}
ProtocolOutput output = protocol.getProtocolOutput(fit.url, fit.datum);
ProtocolStatus status = output.getStatus();
Content content = output.getContent();
ParseStatus pstatus = null;
// unblock queue
((FetchItemQueues) fetchQueues).finishFetchItem(fit);
String urlString = fit.url.toString();
// used for FetchNode
if (fetchNode != null) {
fetchNode.setStatus(status.getCode());
fetchNode.setFetchTime(System.currentTimeMillis());
fetchNode.setUrl(fit.url);
}
reporter.incrCounter("FetcherStatus", status.getName(), 1);
switch (status.getCode()) {
case ProtocolStatus.WOULDBLOCK:
// retry ?
((FetchItemQueues) fetchQueues).addFetchItem(fit);
break;
case ProtocolStatus.SUCCESS: // got a page
pstatus =
output(
fit.url,
fit.datum,
content,
status,
CrawlDatum.STATUS_FETCH_SUCCESS,
fit.outlinkDepth);
updateStatus(content.getContent().length);
if (pstatus != null
&& pstatus.isSuccess()
&& pstatus.getMinorCode() == ParseStatus.SUCCESS_REDIRECT) {
String newUrl = pstatus.getMessage();
int refreshTime = Integer.valueOf(pstatus.getArgs()[1]);
Text redirUrl =
handleRedirect(
fit.url,
fit.datum,
urlString,
newUrl,
refreshTime < Fetcher.PERM_REFRESH_TIME,
Fetcher.CONTENT_REDIR);
if (redirUrl != null) {
fit = queueRedirect(redirUrl, fit);
}
}
break;
case ProtocolStatus.MOVED: // redirect
case ProtocolStatus.TEMP_MOVED:
int code;
boolean temp;
if (status.getCode() == ProtocolStatus.MOVED) {
code = CrawlDatum.STATUS_FETCH_REDIR_PERM;
temp = false;
} else {
code = CrawlDatum.STATUS_FETCH_REDIR_TEMP;
temp = true;
}
output(fit.url, fit.datum, content, status, code);
String newUrl = status.getMessage();
Text redirUrl =
handleRedirect(
fit.url, fit.datum, urlString, newUrl, temp, Fetcher.PROTOCOL_REDIR);
if (redirUrl != null) {
fit = queueRedirect(redirUrl, fit);
} else {
// stop redirecting
redirecting = false;
}
break;
case ProtocolStatus.EXCEPTION:
logError(fit.url, status.getMessage());
int killedURLs =
((FetchItemQueues) fetchQueues).checkExceptionThreshold(fit.getQueueID());
if (killedURLs != 0)
reporter.incrCounter(
"FetcherStatus", "AboveExceptionThresholdInQueue", killedURLs);
/* FALLTHROUGH */
case ProtocolStatus.RETRY: // retry
case ProtocolStatus.BLOCKED:
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_RETRY);
break;
case ProtocolStatus.GONE: // gone
case ProtocolStatus.NOTFOUND:
case ProtocolStatus.ACCESS_DENIED:
case ProtocolStatus.ROBOTS_DENIED:
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_GONE);
break;
case ProtocolStatus.NOTMODIFIED:
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_NOTMODIFIED);
break;
default:
if (LOG.isWarnEnabled()) {
LOG.warn("Unknown ProtocolStatus: " + status.getCode());
}
output(fit.url, fit.datum, null, status, CrawlDatum.STATUS_FETCH_RETRY);
}
if (redirecting && redirectCount > maxRedirect) {
((FetchItemQueues) fetchQueues).finishFetchItem(fit);
if (LOG.isInfoEnabled()) {
LOG.info(" - redirect count exceeded " + fit.url);
}
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_REDIR_EXCEEDED,
CrawlDatum.STATUS_FETCH_GONE);
}
} while (redirecting && (redirectCount <= maxRedirect));
} catch (Throwable t) { // unexpected exception
// unblock
((FetchItemQueues) fetchQueues).finishFetchItem(fit);
logError(fit.url, StringUtils.stringifyException(t));
output(
fit.url,
fit.datum,
null,
ProtocolStatus.STATUS_FAILED,
CrawlDatum.STATUS_FETCH_RETRY);
}
}
} catch (Throwable e) {
if (LOG.isErrorEnabled()) {
LOG.error("fetcher caught:" + e.toString());
}
} finally {
if (fit != null) ((FetchItemQueues) fetchQueues).finishFetchItem(fit);
activeThreads.decrementAndGet(); // count threads
LOG.info("-finishing thread " + getName() + ", activeThreads=" + activeThreads);
}
}